SPARQL query runs through the sparqlService facility of Jena/ARQ, which handles
the HTTP client duties (using its own class named HttpQuery
http://grepcode.com/file/repo1.maven.org/maven2/com.hp.hpl.jena/arq/2.8.7/com/hp/hpl/jena/sparql/engine/http/HttpQuery.java
and returns us a regular jena.query.ResultSet, which we can iterate rowwise, dump as XML, etc.